Filtration assembly including a body, a head, a cartridge and means for retaining the cartridge on the head and the body, and corresponding filtration cartridge

ABSTRACT

A filtration assembly is provided for a liquid flowing in an engine or hydraulic equipment, of the type including a body with a head on top thereof, and a cylindrical member for holding a filtration cartridge containing a filtration medium defined by an upper flange and a lower flange. The upper flange is coupled to the head by a first longitudinal retainer. The cartridge includes a second longitudinal retainer interacting with the body. The first retainer having a longitudinal tensile strength lower than the longitudinal tensile strength of the second retainer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Section 371 National Stage Application ofInternational Application No. PCT/EP2008/053520, filed Mar. 26, 2008 andpublished as WO 2008/125438 on Oct. 23, 2008, not in English.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None.

THE NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT

None.

FIELD OF THE DISCLOSURE

The disclosure relates to the field of designing and producing filteringassemblies used to filter liquids circulating in motors or hydraulicequipment.

BACKGROUND OF THE DISCLOSURE

Such filtering assemblies consist of a filter body inside of which afiltering cartridge is arranged, which generally has a cylindrical shapeand which includes a filtration medium, which can be made for example ofpaper, cardboard or a felt. This filtration medium is conventionallydefined by two end flanges.

Such filtration cartridges generally cooperate with a central tube,secured or not to the flanges, of which the external diameter isadjacent to the internal diameter of the filtration medium so as tolimit deformations of the medium due to the pressure exerted inside thefiltration assembly.

The lower flanges can be extended so as to have means for installing andholding the cartridge in the filtering assembly. Alternatively,filtration assemblies implementing a tube on which the filtrationcartridge is attached are known, in which the tube is permanentlymounted in the filtering assembly.

When the cartridge placed in the tank is used up, i.e. when thefiltering element no longer performs its role of satisfactoryfiltration, the used cartridge of the tank is removed and replaced by anew cartridge. In this change, the operator must extract the cartridgefrom the tank of the filtering assembly in order to be capable ofinserting a new cartridge therein.

According to an approach in which the lifting of the filtering assemblylid leads to extraction of the cartridge, a classic solution consists ofintegrating a support tube in the lid, with the cartridge being held onthe support tube by means of a felt seal.

Handling of these filtering assemblies is not easy in practice.

Moreover, to replace the cartridge, the operator must grab the usedcartridge by hand in order to separate it from the tank and/or from itssupport tube. Aside from the unpleasant sensation that this causes, theoperator's hands quickly become stained with fluids of which theharmlessness cannot be guaranteed (in particular when they contain heavymetals).

To facilitate the extraction of used cartridges, various solutions havebeen proposed.

In particular, according to document DE 197 16 085 a filtering assemblyis known which is equipped with a lid that cooperates by clipping withthe filtration cartridge so that the removal of the lid leads toextraction of the filtration cartridge. The operator then separates thecartridge from the lid by means of any tool, attaches a new cartridge onthe lid and replaces the assembly on the tank. The advantage of thissolution lies essentially in the fact that, during any intervention, theoperator is not forced to directly grab the filtration cartridge andtherefore avoids contact with the liquid.

This type of solution, however, applies in a limited manner totank/lid-type filtering assemblies, i.e. to filtering assemblies inwhich the circulation of liquid is organized by means of the tank.

In such filtering assemblies, the tank is connected to liquid inlet andoutlet conduits and, consequently, is mounted securely on the conduits.In other terms, the filtration cartridge is renewed by removing the lid(which is not coupled to stationary members of its environment otherthan the tank itself), which, once removed, provides access to thecartridge.

According to another type of arrangement of filtering assemblies, thelatter include a head/body assembly in which it is the head (generally asmelted work piece) that is connected to liquid inlet and outletconduits, and the circulation of liquid is therefore organized by meansof this head. In this configuration, once the filtering assembly hasbeen mounted on the conduits, the head is stationary with respect to itsenvironment and the filtration cartridge is renewed by removing the body(for example, by unscrewing it from the head).

However, for this type of configuration, the problem of handling thecartridge during renewal thereof again arises, and this problem cannotbe solved with the existing solutions of “tank/lid” assemblies.

Also, a solution has been proposed by document US 2004 159600, whichdescribes a filtering assembly including a head/body assembly in whichit is the head that is connected to liquid inlet and outlet conduits,and the circulation of liquid is therefore organized by means of saidhead. According to this type of assembly, the head is stationary withrespect to its environment and the filtration cartridge is renewed byremoving the body, by unscrewing it from the head.

The objective of the solution described by this document is to enablethe filtration cartridge to be installed on the head while it is coupledto the body (so as to form a single piece therewith), as well as toenable the separation thereof from the cartridge via the head, while itis also coupled to said body (again forming a single piece therewith).

Therefore, the solution described consists of implementing a ringsecured to the body (either by bonding or by being made in one piecewith the body by molding).

This ring has:

-   -   two studs each having a support surface, between which the upper        flange of the cartridge is intended to be supported;    -   teeth having groove intended to receive an angular portion of        the upper flange of the cartridge.

Thus, before the cartridge is mounted in the filtering assembly, thebody equipped with the ring is mounted on the cartridge, by passing thecartridge through the ring, with the upper flange being introduced intothe groove of the teeth, then supported on the support surfaces of thelugs, and the cartridge is then coupled to the ring and, consequently,to the body supporting the ring.

The detachment of the cartridge from the body is performed in thereverse manner: once the body has been removed from the head, thecartridge must be misaligned with respect to the axis of revolution ofthe ring, in order to separate the upper flange from the supportsurfaces of the lugs, and then to disengage the flange from the groove.

This technique however has a disadvantage.

Indeed, the cooperation of the cartridge with the head involves only theengagement of an extension of the upper flange in a correspondingconduit of the head, with one or more seals being attached to thisextension of the flange.

However, at the end of unscrewing of the body from the head, it is notruled out that, under the effect of gravity, the extension of the upperflange of the cartridge could be disengaged from the head, at a timewhen the operator relaxes his or her grip on the body, thereby causingthe cartridge to fall with the body, involving a risk of soiling thefiltering environment with drainage of the fluid remaining in the body.

SUMMARY

An aspect of the disclosure relates to a filtering assembly for a liquidcirculating in a motor or hydraulic equipment, of the type including abody mounted by a head, and a cylindrical element intended to support afiltration cartridge including a filtration medium defined by an upperflange and a lower flange, characterized in that said upper flange iscoupled to said head by first longitudinal holding means, said cartridgeincludes second longitudinal holding means intended to cooperate withsaid body, and in which said first holding means have a longitudinaltensile strength lower than the longitudinal tensile strength of saidsecond holding means.

A filtering assembly enabling the operator to remove the filtrationcartridge by means of the body, without having to directly grab thecartridge, is thus obtained.

Indeed, it is sufficient for the operator to separate the body from thehead; the removed body includes the cartridge, and it is thensufficient, as will be explained in greater detail below, to separatethe cartridge from the body by a simple and quick manipulation, withoutit being necessary for the operator to grab the cartridge.

The step of removing the body as it holds the cartridge is performed ina manner very simple for the operator owing to the principle of anembodiment of the invention: when the body is separated from the head(it is noted that the head remains stationary during the entirecartridge renewal operation), the first and second longitudinalcartridge holding means are urged, and the first means give under thepulling force exerted by the operator while the second means continue tohold the cartridge.

In other words, when the body is separated from the head, the cartridgeis separated from the head while it is held in the body, without anyparticular intervention by the operator.

In addition, the first means for holding the cartridge on the head ofthe filtering assembly constitute a notch providing an indication to theoperator on the imminence of the detachment of the cartridge (coupled tothe body) from the head. Indeed, at the end of the unscrewing, theoperator perceives a slight resistance due to the first holding means,which indicates that the cartridge and the body are at the point ofbecoming detached from the head and that, consequently, the operatormust keep his or her grip on the body while continuing the unscrewing,so as to prevent the assembly formed by the cartridge and the body fromfalling inadvertently (which could soil the environment of the filteringassembly due to splashes of the fluid still present in the body, or evenspraying of fluid on the operator, or deterioration of this part of theenvironment of the filtering assembly due to any impact ceased by thefall of the body containing the filtration cartridge).

Moreover, as will become clearer below, the first holding means enablethe cartridge to be held on the head for a period of time during whichthe cartridge moves longitudinally inside the body, thereby clearing theway for a drainage passage, as will be explained in greater detailbelow.

According to an advantageous solution, said first holding means areclipping means.

In this way, holding means are obtained with a tensile strength that canbe easily calculated and dimensioned.

Furthermore, such holding means are particularly practical to use forthe operator when installing the cartridge on the head, by enablingsimple and quick installment.

Preferably, said second holding means are borne by said lower flange.

As will become clearer below, it is thus possible to integrate, in thelower existing flange, the second holding means, without majormodifications thereof and without generating significant productioncosts.

In this case, according to an advantageous solution, said second holdingmeans include at least one element projecting radially in the plane ofsaid lower flange, said holding means preferably include four lugsdistributed regularly around said flange, and said body has an annularstop intended to cooperate with said lugs.

Holding means are thus obtained that exert a resistance distributed overthe periphery of the lower flange, again enabling easy calculation anddimensioning, in particular according to the tensile strength of thefirst holding means.

Advantageously, said lugs have a disk portion shape.

In this way, the production of lugs with sharp angles, which, subjectedto stress, are capable of breaking, can be avoided. Instead, the lugbecomes wider at the level of the flange, conferring satisfactory andreliable strength on the lug/flange connection.

According to a specific embodiment, said first holding means have atensile strength of between 30 N and 50 N, and said second holding meanshave a tensile strength of between 90 N and 110 N.

Holding means are thus obtained enabling:

-   -   each to ensure reliable holding of the cartridge;    -   the order of separation of the elements, according to the        principle of an embodiment of the invention, to be ensured;    -   each to ensure a separation without excessive force by the        operator.

According to another feature, said cylindrical element and saidcartridge are secured to one another.

Thus, the number of manipulations necessary in order to renew acartridge are reduced, as the latter and the cylindrical element aremanipulated as a single piece.

According to yet another advantageous feature, said annular stop ispositioned at a height inside said body so as to provide a course oftravel for said cartridge between an operating position and anintermediate extraction position, in which a passage provided in thecentral portion of said body is capable of being released along saidcourse of travel so as to enable said liquid to flow, and said bodypreferably has a base provided with an drainage valve.

It is thus possible, prior to removal of the body from the filteringassembly, to drain the body (whether it contains clean oil or dirtyoil), thereby making it possible:

-   -   for the operator to work under clean conditions;    -   to promote the return of liquid to the corresponding tank,        avoiding the need to manage (store, remove, etc.) the liquid        extracted from the filtering assembly during renewal.

An embodiment of the invention also relates to a filtration cartridgefor an assembly for filtering a liquid circulating in a motor orhydraulic equipment, in which said assembly is of the type including abody mounted by a head, and a cylindrical element intended to supportsaid cartridge, and said cartridge includes a filtration medium definedby an upper flange and a lower flange, characterized in that it includesfirst longitudinal holding means intended to couple said upper flange tosaid head, and second longitudinal holding means intended to couple saidcartridge to said body, and in which said first holding means have alongitudinal tensile strength lower than the longitudinal tensilestrength of said first holding means.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages will become clearer on reading thefollowing description of a preferred embodiment of the invention,provided for illustrative and non-limiting purposes, and the appendeddrawings in which:

FIG. 1 is a cross-section view of a filtering assembly according to anembodiment of the invention;

FIG. 2 is a partial cross-section view of a filtering assembly accordingto an embodiment of the invention, at the level of the first holdingmeans;

FIG. 3 is a partial cross-section view of a filtering assembly accordingto an embodiment of the invention, at the level of the second holdingmeans;

FIG. 4 is a partial cross-section view of a filtering assembly accordingto an embodiment of the invention at the level of the first holdingmeans, in a cartridge extraction phase;

FIG. 5 is a partial cross-section view of a filtering assembly accordingto an embodiment of the invention, at the level of the second holdingmeans, in a cartridge extraction phase;

FIG. 6 is a perspective view of a filtration cartridge of a filteringassembly according to an embodiment of the invention;

FIG. 7 is a view showing the operation of extraction of the filtrationcartridge from a body of a filtering assembly according to an embodimentof the invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

As mentioned above, the principle of an embodiment of the invention liesin the fact of designing a head/body-type filtering assembly so that itincludes cartridge holding means on the head and on the body so that,during disassembly, the holding means on the head give way first.

Such a filtering assembly is shown in FIG. 1, which shows:

-   -   a head 1 (in this case a smelted work piece) having liquid inlet        and outlet conduits and intended to be mounted securely on the        corresponding conduits connected to the liquid tank and to the        motor (or to hydraulic equipment);    -   a body 2, made of plastic material, screwed onto the head 1;    -   a filtration cartridge 3 including a filtration medium 33        extending between an upper flange 31 and a lower flange 32;    -   a cylindrical element 4 (open so as to enable oil to pass into        the central recess 5) forming a support for the cartridge 3 in        the body 2, which element 4 is, according to this embodiment,        secured to the cartridge.

According to the principle of an embodiment of the invention, the upperflange 31 has first holding means (retainer) 34 enabling the cartridgeto be coupled to the head 1, in which the cartridge also includes secondholding means (retainer) 35 intended to cooperate with the body 2.

In reference to FIG. 2, the first holding means 34 are intended tocooperate with the head at least longitudinally, and more specificallyinclude clipping means (clip) formed by a double crown extending fromthe upper flange (and perpendicularly thereto), and the ends of eachcrown are intended to be engaged in an annular groove of the head and tobe supported on a lower edge of the head.

Once the holding means 34 are engaged on the head 1, the cartridge islongitudinally held with respect to the head, with a predeterminedtensile strength of between 30 N and 50 N. In other words, if a pullingforce greater than said predetermined strength is exerted on thecartridge, the holding means are designed to disengage from the head 1,and the cartridge 3 is then separated from the head 1.

Similarly, the second holding means 35 are borne, as shown in FIG. 3, bythe lower flange 32, and are intended to cooperate with an annular stop21 provided on the internal wall of the body 2.

According to this embodiment, the holding means 35 consist of four lugs(FIG. 4) distributed regularly around the flange 32 and projectingradically in the plane thereof.

It is noted that the body 2 is preferably a part obtained by molding aplastic material, and the annular stop 21 is obtained as a direct resultof the molding and the mold removal performed forcefully so as tolongitudinally disengage the corresponding mold imprint of the body, bycausing the stop 21 to bend slightly (the stop has, for the purpose ofindication, a thickness of around 0.5 mm).

In addition, when the lugs 35 are in contact with the stop 21, theyprovide a tensile strength greater than that of the first holding means34. In other words, when an operator exerts a certain longitudinalpulling force on the cartridge with respect to the body 2, the lugs 35and/or the stop 21 are intended bend and enable the cartridge 3 to beextracted from the body 2.

By way of indication, the lugs have:

-   -   a thickness of 2 mm;    -   a tensile strength greater than that of the holding means 34,        between 90 N and 110 N.

It is also noted that, as shown in FIG. 4, the lugs 35 have a roundshape and extend from the lower flange 32 according to a portion of thedisk.

In addition, the annular stop 21 is positioned at a height inside thebody 2 so that, when the filtering assembly is operating, the lowerflange 32 (and therefore the lugs 35) is below the stop 21.

Thus, during disassembly, the flange 32 travels over a course c (on theorder of 12 mm according to this embodiment) before the lugs come intocontact with the stop 21.

In addition, the central sleeve 23 (on which the cylindrical elementfits 4) extending from the base 22 of the body 2 has a decrease in itsexternal diameter so that, when the cartridge moves in translation overthe course c, a passage is formed (between the internal diameter of thecartridge 3 and the external diameter of the sleeve 23) so as to enablethe liquid to flow toward the base of the body 2.

The liquid collected in the base of the body 2 can then be emptied bymeans of a drainage valve 6.

The assembly and disassembly of a filtration assembly like thatdescribed above is explained below.

A filtration cartridge is installed as follows:

-   -   the filtration cartridge 3 is longitudinally inserted into the        body 2, and stress is required to force the lugs 35 to pass over        the stop 21 of the body;    -   the longitudinal engagement of the cartridge in the body is        continued until the cylindrical element 4 is fitted on the        sleeve 23 and the lower flange 32 is in contact with an annular        stop 24 (FIG. 3);    -   the body 2 integrating the cartridge is screwed onto the head 1,        and this operation is accompanied by the engagement of the first        holding means 34 in the head 1 (FIG. 2), the screwing being        continued until the body 2 is tightly connected to the head 1.

The cartridge is extracted as follows:

-   -   the unscrewing of the body 2 from the head 1 is begun: during a        first unscrewing phase, the cartridge remains engaged on the        head, thereby causing a translation movement of the cartridge        with respect to the body 2, over a distance corresponding to the        course c (FIG. 5); the passage of clean liquid (in the central        recess) is then allowed between the sleeve 23 and the central        recess of the cartridge (as shown by the arrows F indicated in        FIG. 5), while the dirty liquid (between the walls of the body 2        and the medium 33) flows between the lugs;    -   the drainage valve 6 is opened to extract the liquid collected        at the bottom thereof from the body 2;    -   the unscrewing of the body 2 is continued until the lugs 35 come        into contact with the stop 21, and the cartridge and the body        are secured in translation, thereby tending to produce a pulling        force on the cartridge with respect to the head until said force        causes the first holding means 34 to be disengaged from the        complementary means 340 of the head 1 (FIG. 4); to obtain the        disengagement of the first holding means from the complementary        means of the head, the operator perceives a slight resistance to        the unscrewing, which resistance indicates that the cartridge is        at the point of becoming detached from the head and that it is        necessary to keep hold of the body while continuing the        unscrewing in order to prevent the body containing the cartridge        from falling inadvertently at the end of the unscrewing; after        complete unscrewing, the body 2 and the cartridge are separated        from the head 1;    -   the cartridge is extracted from the body, for example by        inserting a tool 7 (as shown in FIG. 5) under holding means 34        so as to exert a lever effect on the cartridge while holding the        body, which lever effect must be greater than the tensile        strength of the holding means 35 (thereby causing a slight        deformation of the lugs and/or of the stop enabling the lugs to        pass over the stop).

In one example, an embodiment of the invention is intended to propose ahead/body-type filtering assembly that enables the filtration cartridgeto be replaced without requiring the operator to directly contact it.

An embodiment of the invention is also intended to provide such afiltering assembly that enables the filtration cartridge to be installedand removed quickly and easily.

Another objective of an embodiment of the invention is to provide suchan assembly that enables the filtering assembly to be easily emptiedbefore it is replaced.

An embodiment of the invention is also intended to provide such afiltering assembly that has a simple design, is easy to implement andinexpensive to produce.

Although the present disclosure has been described with reference to oneor more examples, workers skilled in the art will recognize that changesmay be made in form and detail without departing from the scope of thedisclosure and/or the appended claims.

The invention claimed is:
 1. A filtering assembly for a liquidcirculating in a motor or hydraulic equipment, the filtering assemblycomprising: a body mounted by a head; a cylindrical element; and afiltration cartridge supported by the cylindrical element and includinga filtration medium delimited by an upper flange and a lower flange,wherein said upper flange is coupled to said head by first longitudinalholding means, wherein said filtration cartridge includes secondlongitudinal holding means cooperating with said body, said lower flangecomprising said second holding means, wherein said first holding meanshave a longitudinal tensile strength lower than the longitudinal tensilestrength of said second holding means, wherein said second holding meansinclude at least one element projecting radially in a plane of saidlower flange configured for cooperating with an annular stop provided onan internal wall of said body, and wherein said annular stop ispositioned at a height inside said body so as to provide a course oftravel for said cartridge between an operating position and anintermediate extraction position, in which a passage provided in acentral portion of said body is capable of being released along saidcourse of travel so as to enable said liquid to flow.
 2. The filteringassembly according to claim 1, wherein said first holding means compriseclipping means.
 3. The filtering assembly according to claim 1, whereinsaid second holding means include at least one element projectingradially in a plane of said lower flange.
 4. The filtering assemblyaccording to claim 3, wherein said second holding means include fourlugs distributed regularly around said flange, in which an annular stopcooperates with said lugs.
 5. The filtering assembly according to claim4, wherein said lugs have a disk portion shape.
 6. The filteringassembly according to claim 1, wherein said first holding means have atensile strength of between 30 N and around 50 N, and said secondholding means have a tensile strength of between 90 N and around 110 N.7. The filtering assembly according to claim 1, wherein said cylindricalelement and said cartridge are secured to one another.
 8. The filteringassembly according to claim 1, wherein said body has a base providedwith a drainage valve.
 9. A filtration cartridge for a filteringassembly for filtering a liquid circulating in a motor or hydraulicequipment, and a cylindrical element intended to support said cartridge,wherein the cartridge comprises: a filtration medium delimited by anupper flange and a lower flange, first longitudinal holding meansconfigured to couple said upper flange to a head of the filteringassembly, and second longitudinal holding means comprises by the lowerflange and configured to couple said cartridge to a body of thefiltering assembly, wherein said first holding means have a longitudinaltensile strength lower than the longitudinal tensile strength of saidsecond holding means, wherein said second holding means include at leastone element projecting radially in a plane of said lower flange andconfigured to cooperate with an annular stop provided on an internalwall of said body of the filtering assembly, and wherein said cartridgehas a course of travel between an operating position and an intermediateextraction position, in which a passage provided in a central portion ofsaid body of the filtering assembly is capable of being released alongsaid course of travel so as to enable said liquid to flow.